Washing machine appliances generally include a tub for containing wash fluid, e.g., water, detergent, and/or bleach, during operation of such washing machine appliances. A drum is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During operation of such washing machine appliances, wash fluid is directed into the tub and onto articles within the wash chamber of the drum. The drum can rotate at various speeds to agitate articles within the wash chamber in the wash fluid, to wring wash fluid from articles within the wash chamber, etc.
During operating of certain washing machine appliances, a volume of water is directed into the tub in order to form wash fluid and/or rinse articles within the wash chamber of the drum. The volume of water can vary depending upon a variety of factors. Large loads can require a large volume of water relative to small loads that can require a small volume of water. Likewise, loads containing absorptive fabrics, such as cotton, can require a large volume of water relative to similarly sized loads containing certain synthetic fabrics, such as polyester or nylon.
To operate efficiently, the volume of water directed into the tub preferably corresponds or correlates to a size of a load of articles within the wash chamber of the drum and/or a load type of articles within the wash chamber of the drum. Thus, large volumes of water are preferably directed into the washing machine's tub for large loads or loads of highly absorptive articles in order to properly wash such loads. Conversely, small volumes of water are preferably directed into the washing machine's tub for small loads or loads of poorly absorptive articles in order to properly wash such loads. Directing an improper volume of water into the drum can waste valuable water and/or energy and can also hinder proper cleaning of articles within the wash chamber of the drum. However, accurately determining the size and/or type of a load of articles within the wash chamber of the drum can be difficult.
Accordingly, a method for detecting underfilling of a washing machine appliance would be useful.